Cordless surgical handpiece with disposable battery; and method

ABSTRACT

A surgical procedure is disclosed utilizing a cordless surgical handpiece powered from a sterile battery pack that contains a battery in condition for immediate use without further charging or sterilization. The battery chemistry is based upon lithium/manganese dioxide, and the battery after a single use may be disposed of into non-hazardous waste. The compact surgical handpiece has a brushless DC motor and a manually operated external trigger for activating and controlling the motor operations. Interengaging sets of contacts on the handpiece and battery are adapted to become lockingly and conductively interengaged upon rotation of the battery pack relative to the handpiece, in a manner that rapidly achieves correct alignment of the parts and also ensures stable mechanical attachment and support during the surgical procedure.

PRIORITY CLAIM

This application claims the benefit of our application Ser. No.09/349,643 filed Jul. 8, 1999 now U.S. Pat. No. 6,126,670 and of ourProvisional Application 60/112,678 filed Dec. 16, 1998.

FIELD OF THE INVENTION

The present invention relates to electrically operated surgical toolsand methods of their use.

BACKGROUND OF THE INVENTION

An important economic factor for any surgical tool or machine is theamount of unproductive time spent in its operation. This comes in theform of training and initial set-up. Before a surgical procedure begins,the users need to know how to operate the instrument and be familiarwith all its controls. Hospital personnel must set up the instrumentsystem before it can be used. This involves connecting all the powerlines, calibration, and verifying function. Both user's training andinstrument system set-up entail time and cost by the medical facility.

The most unique aspect of surgical equipment is the need for sterility.To prevent infections and to aid healing, surgical equipment issterilized. The effort this takes and the success with which it occursvaries depending on the equipment. The maintenance of sterility in thesurgical site is a major factor in health care. Non-sterile or partiallysterile instruments may be considered to harbor bacteria or toxicdebris. Each of these will lead to an inflammatory response from thebody and associated infection, carcinogenosis and cell necrosis.Contamination will lead to grave systemic effects on the patients oforthopedic surgery, which by its nature is highly invasive. Themaintenance of a sterile operating field is of prime importance insurgical handpieces.

Corded Instrument Systems

The use of a corded instrument system dictates that only one handpiecemay be used at any one time per console. When another instrument isneeded the console cord must be switched to another instrument.Procedures where it is imperative that two instruments be usedsimultaneously necessitate two consoles. Handpiece instrument consolesare expensive and the need for duplication is a distinct disadvantage.Disconnecting and reconnecting instruments to the console cord takes acertain amount of work and time. Using cordless instruments reducesinstrument transfer time.

A reusable cord must be properly sterilized prior to surgery in anexpensive and complex in-house sterilizer. Once sterile, the cord mustbe carefully transported to the operating room. There the cord becomespartially non-sterile due to its console connection.

When a corded handpiece is transferred and exchanged to other medicalpersonnel, the cord must be handled. However, there is no way to tellwhich part of cord has fallen out of the sterile field. This poses anincreased risk of contamination to the user and the surgical site.

When multiple handpieces are exchanged they are extensively handled.This is because the cord must be disconnected and reconnected to eachhandpiece. Handling increases the risk of contamination. This risk isgreatly minimized with cordless instruments.

Following a surgical procedure, the instrument cord needs to bethoroughly cleaned prior to its next use. This involves cleaning bloodand tissue off the cord with powerful solvents and cleaners. Theseagents attack the cord and limit its useful life. The cord must behandled by trained medical personnel. A disposable power pack wouldeliminate these extra tasks and their associated costs.

Cordless Instruments

During a surgical procedure it is often necessary to use more than onehandpiece. Saws and high speed handpieces are used for cutting, shapingand in general removing portions of bone. Drills are used primarily formaking holes, which are then used for inserting wires, pins or screws.These two operations are often used in conjunction with one anotherduring bone and tissue repair procedures. Current pencil grip surgicalinstruments make it difficult to use more than one instrument at a timeduring a surgical procedure.

A cordless handpiece is easier for the physician to operate than similarcorded handpieces. The controls are basic and are controlled with onehand. Equivalent corded handpieces require complex console instructionsand commands.

A further advantage of cordless handpieces is the greater ease ofset-up. Equipment set-up is a significant time issue for hospitals.Corded systems have complicated and time-consuming assembly procedures.Multiple connections are involved. A user must be trained at setting upand operating the console system.

In instances where a powered surgical instrument is needed immediately,a cordless instrument can be immediately transported to that area. Thisis true regardless of the surrounding environment. That is not true of acorded unit.

A surgical instrument cord, connected to a non-sterile console, may beconsidered only partially sterile. This by itself compromises theintegrity of a surgical site. A cordless handpiece maintains sterilitythroughout the entire surgical operation.

Surgical procedures often involve cuts at more than one position at asurgical site. A convenient way to accomplish this is to pass thesurgical instrument over the surgical site. With a corded instrument,this would unfortunately result in the cord being passed over, andperhaps falling into, the surgical site. The resulting tissue damage andcontamination can have grave consequences. A cordless instrument caneasily be passed over the surgical site without contamination risks.Likewise, a physician who needs to make multiple cuts or holes atvarious surgical locations needs to be in the position that best suitedhim or her without trailing a bulky, cumbersome partially sterile cord.

Cordless instruments have heretofore utilized batteries of therechargeable type. This adds special problems, because the battery mustbe sterilized before use; and after each use it must be recharged andthen sterilized in preparation for the next use. Presently availablebatteries do not lend themselves well to this process.

SUMMARY OF THE INVENTION

According to the present invention a method of performing surgery isprovided, in which bone or hard tissue may be cut, shaped, or drilled bymeans of a cordless powered surgical instrument, but without thenecessity of subsequently recharging a battery or re-establishing itssterile condition.

According to the invention a disposable battery pack can be easilyconnected to a surgical instrument, both electrically and mechanically,and after a single use may be detached and safely disposed of asnon-hazardous waste, into the waste system.

Further according to the invention a method of performing a surgicalprocedure is disclosed, utilizing a cordless surgical handpiece poweredfrom a sterile battery pack in which the battery chemistry is based uponlithium/manganese dioxide, the battery being in condition for immediateuse without further charging or sterilization, and being adapted after asingle use to be disposed of into non-hazardous waste.

Still further according to the present invention a surgical handpieceand disposable battery are provided with mating sets of electricalcontacts which can be mechanically and conductively locked together toensure correct alignment of the parts, as well as stable mechanicalsupport and reliable electrical operation of the handpiece during thesurgical procedure.

According to yet another feature of the presently preferred form of theinvention, a surgical handpiece and a disposable battery each has adefined longitudinal axis with a set of electrical contact elementsarranged generally concentric to that axis, and when those parts arealigned on a mutual longitudinal axis the sets of contacts are adaptedto become lockingly and conductively interengaged in response torotation of the battery pack relative to the handpiece.

Still another feature of the invention is that when using a compactsurgical handpiece with a brushless DC motor and a manually operatedexternal trigger for activating and controlling the motor operations, acompatible disposable battery may also be used, with interengaging setsof contacts on the handpiece and battery adapted to become lockingly andconductively interengaged upon rotation of the battery pack relative tothe handpiece in a manner that rapidly achieves correct alignment of theparts and also ensures stable mechanical attachment and support duringthe surgical procedure.

DRAWING SUMMARY

FIG. 1( a) is a schematic view of a surgical handpiece in accordancewith the invention, showing disposal of an associated battery pack intonon-hazardous waste after it has been used;

FIG. 1( b) is a cross-section view taken on the Line 1(b)—(1(b) of FIG.1( a), showing that the battery pack when being disposed of stillcontains batteries;

FIG. 2 is a perspective view of a sterile battery pack in its plasticcontainer, in accordance with the invention;

FIG. 3 is an exploded perspective view of the handpiece and battery packbefore they are assembled together;

FIG. 4 is a perspective view of the instrument assembly duringattachment of the battery pack, with arrows indicating the direction ofmovement of the battery pack;

FIG. 5 is a perspective view of the instrument assembly after attachmentof the battery pack, with arrows showing that the battery pack has beenrotated by ninety degrees;

FIG. 6 is a rear end view of a surgical drill or handpiece in accordancewith the invention taken along line 6—6 of FIG. 3;

FIG. 7 is a front end view taken along line 7—7 of FIG. 3 of thedisposable battery pack;

FIG. 8 is a longitudinal cross-sectional view showing initial alignmentof the battery pack to the surgical drill;

FIG. 9 is a cross-sectional view like FIG. 8, but showing the batterypack after its full insertion and its rotation into a lockingattachment;

FIG. 10 is a perspective view of the battery pack showing in detail itsforward end;

FIG. 11 is a perspective view of the batteries contained within thebattery pack;

FIG. 12 is a side elevation view of the battery pack; and

FIG. 13 is a perspective view of a complete instrument showing analternate form of trigger for handpiece control.

DETAILED DESCRIPTION

In FIGS. 1( a) and 1(b) a surgical handpiece 10 with housing 12 has arearward or base end 14, an externally mounted trigger 16, and a tool 18on its forward end. A disposable battery pack 20 has a housing 22 andcontains internal batteries 24. Arrow 30 indicates the disposal ofbattery pack into a waste basket 32 after the surgical handpiece hasbeen used in a surgical procedure.

As is conventional, the surgical handpiece is a compact devicecontaining a brushless DC motor for moving the tool member 18, amanually operated trigger 16 used for activating motor controloperations, and an adjustable tool support mechanism for orienting thetool 18 and securing it in place. An electronic circuit, notspecifically shown, controls and regulates the energy supply to themotor, and is operated externally by the trigger 16. Trigger 16 may alsocontrol the range of speed, the direction of the cutting tool, andcutting tool braking.

According to the present invention the energy supply for the handpieceis provided by the battery pack 20 which is secured onto the handpieceby means of a rotating movement. This detachable DC electric energysupply ensures correct orientation of the electrical contacts in thebattery to those for the handpiece, and also signals to the operator bysound, sight, and touch that the battery is correctly secured in place.

The battery pack 20 is pre-sterilized and packaged for immediate use ina surgical environment. FIG. 2 shows a plastic cover 26 which ispreferably used to enclose the battery pack prior to its use. Thebattery pack 20 consists of primary batteries 24 which by definition donot require charging before use. These batteries retain their initialcharge for long periods of time. The battery pack is discarded after useand may be considered a disposable component of the instrument system.

Further according to the invention the battery pack preferably containsprimary batteries 24 whose chemistry is based upon lithium/manganesedioxide, such as the DL 2/3A manufactured by Duracell, Inc. of Bethel,Conn. These batteries possess a high energy density, have a high ratecapability over a broad temperature range, and have excellent capacityretention.

As shown in FIG. 3 the handpiece 10 at its rearward or battery receivingend 14 has an alignment post 40 extending therefrom, which defines alongitudinal axis of the handpiece. It also has a set of electricalcontact elements 42 a and 42 b which are concentric to that axis. Thesterile and disposable battery pack 20 has an attachment end 50 with acentral opening 52 therein, the opening 52 also defining a longitudinalaxis of the battery pack. The battery pack 20 also has a set ofelectrical contact elements 54 which are concentric to its longitudinalaxis. The central opening 52 in the disposable battery pack 20 isadapted to insertably receive the alignment post 40 so as to establish amutual alignment axis of the handpiece 10 and battery pack 20.

The battery receiving end of the handpiece 10 also has flat end surfacesurfaces 44 a and 44 b which are adapted to be engaged by the batterypack. The forward or attachment end of the disposable battery pack has aflat end surface 56 adapted for abutting engagement with the endsurfaces 44 a and 44 b while yet allowing relative rotation of thebattery pack relative to the handpiece.

The set of contacts 42 a and 42 b on the battery receiving end of thehandpiece and the set of contacts 54 on the attachment end of thedisposable battery pack are mating sets of electrical contact elements,each set being arranged generally concentric to the mutual alignmentaxis. Upon the insertion of the alignment post 40 of the handpiece intothe opening 52 of the battery pack, the sets of mating contacts areadapted to then become lockingly and conductively interengaged inresponse to rotation of the battery pack relative to the handpiece.

In operation, the post 40 is first partially inserted into opening 52 toestablish alignment of battery and handpiece. Then with furtherinsertion, the two sets of contacts will assume a position in concentricrelation to their common mutual axis of alignment.

The Interlocking Parts

Referring now to FIGS. 3, 6, 8, 9, and 12, the detailed structure of therearward end of handpiece 12 is shown. Rearward end 14 of the housing ofhandpiece 12 has an aluminum cover. An end plate 60 made of aluminumcloses the rearward end of handpiece housing, as best seen in thecross-section views of FIGS. 8 and 9. End plate 60 is recessed inwardlyfrom the extreme rearward end of the housing.

There are a pair of electrical contacts 42 a and 42 b which protrude outfrom end plate 60. Those contacts do not support themselves, however; aplastic cylinder 62 is secured to end plate 60, and the contacts 42 a 42b, are secured to the outer wall of plastic cylinder 62, about 180degrees apart. One contact is of course positive, and the othernegative.

The rearward end of the handpiece also has flanges that are part of andprotrude outward from end plate 60 to control the insertion and lockingof the battery pack, designated on FIG. 3 by numerals 44 a and 44 b. Onthe left side as seen in FIG. 3, there is a wide gap between 44 a and 44b. On the right side as seen in FIG. 3, there is a narrow gap. Theflanges are preferably formed as an integral part of the end plate 60,as shown in FIG. 8. A stop pin 65 seen in the upper right portion ofFIG. 6 protrudes inwardly behind flange 44 b and limits the rotation ofthe battery contacts relative to the handpiece.

The front end of battery pack 20 is shown in FIGS. 3, 7, 8, 9, and 10.It has a front end plate 70, formed of plastic material, such as ABSplastic; see FIG. 8. End plate 70 also has a projecting ring 72, withflanges 74, 76. As best seen in FIG. 3, flange 74 on the near side ofthe battery pack will fit into the gap between lower flange 44 a andupper flange 44 b of the handpiece, which gap is also on the left asseen in FIG. 3.

The other flange 76 on far side of battery pack will fit between flanges44 a, 44 b on the far or right side of the handpiece as seen in FIG. 3.However, flange 74 is too wide to enter the gap on the right side asseen in FIG. 3. Therefore, battery pack 20 must be engaged with thehandpiece in a predetermined relative position.

FIG. 8 shows alignment of the two parts of apparatus on their mutuallongitudinal axis as the post 40 makes its initial entry into the centerhole 52 of the battery pack. Further insertion of the post ensures thecoaxial alignment of the two parts.

Rotating the Battery Pack to Locked Position

Then battery pack 20 is rotated to the right, as indicated by arrows 80in FIGS. 3, 4, and 5. FIG. 5 shows the locked position, also shown inmore detail in FIG. 9. Further rotation of the battery pack relative tothe handpiece is prevented by the stop pin 65. The contact elements 42 aand 42 b are made as spring members, so that when the contact elements54 of the battery pack are seated, there is an audible noise to tell theoperator that the properly aligned operating position has been reached.Thus the apparatus includes means providing a spring-supported snapaction so that the sets of mating contacts become lockingly andconductively interengaged in response to rotation of the battery packrelative to the handpiece.

It will also be noted that the battery receiving end of the handpiece,and the attachment end of the battery pack, each has a non-circularexternal cross-sectional configuration. Thus in the presently preferredembodiment of the invention the two housings are essentially square withrounded corners. The two external configurations are closely similar inboth size and shape, and the rotational position of the battery packwhen the contacts are locked together is such that the handpiece and thebattery pack then provide an essentially continuous external surface.This indicates to the hand of the operator that correct alignment of thecontacts has been achieved.

Advantages of Cordless Surgical Handpieces

Orthopedic surgical instruments are widely used in many delicate boneworking procedures. These include spinal surgeries, neurosurgeries andother bone sculpting operations. For these surgeries, a small, lightweight, well balanced instrument is desired. The handpiece needs to havehigh speed and power, and be sterilizable.

The ergonomics of a pencil grip cordless instrument is quantifiablybetter than corded or pistol grip handpieces. Pencil grip allows more,fine motor control and easier eye-hand coordination. The improvedergonomics of the pencil grip results in less fatigue by the user.

A cordless handpiece is more mobile than a corded unit. This makes iteasier to pass it around the surgical site, from physician to attendantor assistant. A cordless system is also not weighed down by a cord. Theback of corded or pistol grip handpieces can require tugging or liftingof the handpiece cutting tool, which makes cutting more difficult. Thecord diameter is very thick for a high performance system, which againlimits mobility.

A further disadvantage of a corded instrument is that it is tethered.The handpiece can only be operated at a given distance from the console,restricted by the length of the cord. The cord also has associatedinductance and capacitance properties which can affect the handpieceperformance or electrical complexity of the system.

For movement about the surgical site with a corded handpiece, extra cordis needed. The extra cord is either coiled by the physician, held by anattendant or attached to a surgical stand. This coiling necessitatesextra labor by operating room (OR) personnel, takes up critical surgicalsite space and limits mobility of other OR personnel.

The mobility and transport of cordless, pencil grip instruments is ofparticular advantage when multiple instruments are needed in aprocedure. This is often the case where drilling, sawing and wiredriving are all needed. These often come in rapid succession and indifferent sequences. Time is a critical factor for successful surgicaloutcomes.

Electrical Advantages of Cordless Instruments

Instrument performance is of critical importance in surgical procedures.A key electrical factor with corded handpieces is the cord itself. Thepower cord has a given length associated with it and electricalproperties of its own.

The internal impedance of the cord increases electrical losses andreduces power and performance. The power is lost as heat and many haveother electro-magnetic interference (EMI) problems associated with it.The length of cord and flexibility needed usually necessitate the use ofthree-phase current.

The cord also has associated inductance and capacitance properties whichreduces performance and necessitates more complex electronics in theconsole. There are also associated EMI problems with this inductance andimpedance. These factors exist with both DC and, especially, AC signals.

The electrical properties of the cord are directly proportional to itslength and can only be minimized by shortening the cord or making itthicker. A shorter cord reduces mobility. A thicker cord reducesflexibility and increases costs.

The EMI problems associated with a cord occur along the entire cordlength. The two connections are especially prone to emissions. Cordlessinstruments, on the other hand, run on direct current (DC), have onlyone connection point and minimized electronics. The basic level ofemitted EMI from the battery to handpiece connection, in a cordlesshandpiece, is zero.

A corded surgical instrument has a direct connection between the patientand wall or line voltage. Power surges from the outlet must be properlycontrolled before they reach the patient. A cordless instrument whichoperates with lower voltage, less energy, and a limited capacity powersupply, poses a much lower electrical threat to the patient.

The calibration and preventive maintenance costs associated with acorded handpiece console are not a factor with a cordless system. Theelimination of the console results in more operating room table space.This valuable space can then be used for important instruments andequipment which need to be close at hand.

Cost and Reliability of Cordless Systems

The cost and reliability of any surgical instrument is of criticalimportance. OR expenses are high and are based on time usage. Allgeneral surgeries have a time factor based on how long the room isoccupied and the patient is under anesthesia. Instrument systems mustproperly work or the operation's success, and thus the patient's health,will be affected.

Cord breakage or damage is a prevalent problem and necessitates cordreplacement or repair. Cord failure may also damage the handpiece and/orconsole through electrical shorts or otherwise. Even partial failurewill directly decrease the performance of the surgical system. Cordrepair and replacement is expensive, as is system repair andreplacement.

Due to the high failure rate of cords, as well as their importance tothe handpiece system, they must be tested often. This results in timeand expense to the medical facility, even when they are functional.

Cord damage may result in heat build-up or exposed electrical leads.These pose serious risks to the operators as well as the patient.

Sterilization and cleaning using hospital grade detergents have seriousnegative effects on the cord. These thermal and chemical agents directlyreduce the life of the cord, as well as increase the likelihood ofdamage.

Cord damage may also result in improper system communications andlinkage. This may result in increased cord impedance and consequent lossof handpiece performance. Improper signaling may also lead to impropermotor operations and result in handpiece overheating. This may be ahazard to either the user, patient or attending personnel.

Advantages of Disposable Battery Packs

The high operating costs of surgical arenas and medical personneldictate the use of low maintenance, easy to use equipment. Many timesthis means single use or disposable components. Also supportingdisposable product use is the issue of sterility and contaminants fromthe surgical site. Surgical equipment is often made disposable wheneverpossible. Packaged pre-sterile, disposable medical equipment, by itsnature, is easy to use and maintain and often very cost-effective.

Disposable, primary battery packs offer a higher energy capacity pervolume than equivalent rechargeable batteries. The batteries aresmaller, which is a distinct advantage in cordless surgical handpieces.

Disposable, primary battery packs offer a higher energy capacity perweight than equivalent rechargeable batteries. The batteries arelighter, which is a distinct advantage in cordless surgical handpieces.

Disposable batteries are inspected at the manufacturer by trainedpersonnel prior to each use. This gives the products a higherreliability per use than equivalent reusable batteries. This is anadvantage during critical use situations that often occur in theoperating room.

Every battery pack has full running power immediately upon attachment.Rechargeable batteries, on the other hand, must be tested to verifytheir immediate charge capacity.

Due to the nature of disposable batteries there is no pre- or postoperation clean-up involved. This reduces the amount of time hospitalpersonnel need to service the equipment.

Reusable batteries will exhibit wear after repeated use. This results indebris build-up on components, particularly oxidation on electricalcontacts, weakening of the housing and general degradation. This mayresult in poor or unacceptable product performance. Disposable productsdo not have these associated problems.

Disposable, primary batteries may be entered into the normal wastestream. Standard rechargeable batteries are considered toxic and must beproperly disposed of outside the normal waste stream.

Most disposable primary batteries may be transported by air or otherstandard methods. Some types of rechargeable batteries need specialhandling conditions and permits to be safely transported.

By their very nature disposable primary battery cells have an immediatecharge capacity, unlike rechargeable battery cells. Rechargeablebatteries need to be charged on specialized and dedicated chargers. Thisis an expensive and bulky piece of equipment for the medical facility.

Rechargeable, secondary batteries need to be recharged immediately priorto each use because they lose their electrical charge very quickly.Primary batteries retain their charge for very long periods of time,over ten years. This results in lower service and maintenance costs tohospital for disposable batteries.

Primary batteries have a much lower cost base than equivalentrechargeable batteries. This usually has the advantage of saving moneyfor medical facilities.

Disposable primary cells generally have a higher voltage, and thus ahigher energy potential than rechargeable cells. Furthermore, a highervoltage allows most standard electrical and electromechanical componentsand motors to operate more efficiently, with fewer components, at alower cost.

Disposable, primary batteries retain their charge capacity under morevaried conditions, including thermal, humidity and mechanical (e.g.vibration or shock) than equivalent rechargeable battery cells. Thisincreased robustness is an advantage in surgical operations.

In improper use conditions, such as a short circuit, many types ofbatteries will vent their internal electrolyte in the form of a gas. If,due to improper conditions, primary batteries vent internal gas, thesegases are non-toxic. This is unlike some types of rechargeablebatteries. That can be a critical issue in an operating room where itwould be very difficult to evacuate the area if this condition arose.

Alternate Embodiment

In the alternate embodiment of the present invention as shown in FIG.13, the handpiece 10′ has a rather long-handled trigger 16′.

While the presently preferred embodiment of the invention has beendisclosed in detail in order to comply with requirements of the patentlaws, it will be understood by those skilled in the art that somevariations may be possible within the concept of the invention. It willtherefore be understood that the scope of the invention is to bedetermined only in accordance with the appended claims.

1. A surgical instrument comprising: (a) a handpiece having a toolsupporting end, and a battery receiving end, the battery receiving endhaving: a first set of substantially concentrically arranged electricalcontacts; and first and second opposing flanges substantiallyperpendicular to and opposing a longitudinal axis of the handpiece andseparated by first and second gaps of substantially different widthsopposing the longitudinal axis; and (b) a sterile package comprising asingle surgical use, disposable battery pack having an attachment end,the attachment end having; a second set of substantially concentricallyarranged electrical contacts; and third and fourth flanges opposing thehandpiece longitudinal axis, substantially parallel to and slidablyengaged with the first and second opposing flanges, and configured topass through a corresponding one of the first and second gaps in asingle, predetermined relative position; (c) wherein the two sets ofcontacts are adapted to become lockingly and conductively interengagedupon engagement of each of the third and fourth flanges with acorresponding one of the first and second flanges in response torotation of the battery pack relative to the handpiece.
 2. A surgicalinstrument as in claim 1 wherein the battery pack has chemistry basedupon lithium/manganese dioxide, the battery pack after use beingdisposable into non-hazardous waste.
 3. The surgical instrument as inclaim 1 further comprising a surgical tool coupled to the toolsupporting end and configured for performing a cutting operation on livehuman bone or hard tissue.
 4. The surgical instrument as in claim 1further comprising a surgical tool coupled to the tool supporting endand configured for performing a drilling operation on live human bone orhard tissue.
 5. The surgical instrument as in claim 1 further comprisinga surgical tool coupled to the tool supporting end and configured forperforming a shaping operation on live human bone or hard tissue.
 6. Asurgical instrument for performing a cutting, shaping, or drillingoperation on live human bone or hard tissue, comprising: (a) a handpiecehaving a battery receiving end with an alignment post extendingtherefrom and a tool supporting end for supporting a tool for performinga cutting, shaping, or drilling operation on live human bone or hardtissue; and (b) a sterile package containing a single use, disposablebattery pack which has an attachment end with a central opening therein;(c) the central opening in the single use, disposable battery pack beingadapted to insertably receive the alignment post so as to establish amutual alignment axis of handpiece and battery pack; (d) the batteryreceiving end of the handpiece and the attachment end of the single use,disposable battery pack having flat end surfaces adapted for abuttingengagement while yet allowing relative rotation of the battery packrelative to the handpiece; (e) the battery receiving end of thehandpiece and the attachment end of the single use, disposable batterypack having mating sets of electrical contact elements, each set beingarranged generally concentric to the mutual alignment axis; and (f)wherein upon the insertion of the alignment post of the handpiece intothe opening of the battery pack, the sets of mating contacts are adaptedto then become lockingly and conductively interengaged in response torotation of the battery pack relative to the handpiece.
 7. The apparatusof claim 6 wherein the chemistry of the disposable battery pack is basedupon lithium/manganese dioxide.
 8. The apparatus of claim 6 includingmeans providing a spring-supported snap action whereby the sets ofmating contacts become lockingly and conductively interengaged inresponse to rotation of the battery pack relative to the handpiece. 9.The apparatus of claim 8 wherein the spring-supported snap action meansprovides an audible sound indicating that the mating contacts and thebattery have been correctly and securely locked in position.
 10. Theapparatus of claim 6 wherein the battery receiving end of the handpiece,and the attachment end of the battery pack, each has a non-circularexternal cross-sectional configuration, the two external configurationsbeing closely similar in both size and shape, and the rotationalposition of the battery pack for locking the contacts being such thatthe handpiece and the battery pack then provide an essentiallycontinuous external surface which indicates to the hand of the operatorthat correct alignment of the contacts has been achieved.
 11. Theapparatus of claim 10 including means providing a spring-support snapaction whereby the sets of mating contacts become lockingly andconductively interengaged in response to rotation of the battery packrelative to the handpiece.
 12. A surgical instrument for performing asurgical drilling procedure on bone or hard tissue, comprising: (a) ahandpiece having a rotary driven drilling member supported by a toolsupporting end, and a battery receiving end with an alignment postextending therefrom, the battery receiving end of the handpiece alsohaving a set of electrical contact elements arranged in generallyconcentric relation to the alignment post; (b) a disposable batteryhaving an attachment end with a central opening therein, and a set ofmating electrical contact elements arranged in a generally circularconfiguration concentric to the central opening therein; (c) the centralopening in the disposable battery being adapted to receive the alignmentpost of the handpiece in a partially inserted position so as toestablish a pre-attachment alignment thereof; (d) the sets of matingcontacts being adapted to come into a mutually concentric relation inresponse to a further insertion of the alignment post into the centralopening; and (e) the sets of contacts being adapted to then becomelockingly and conductively interengaged upon rotation of the batterypack relative to the handpiece.
 13. The apparatus of claim 12 whereinthe chemistry of the disposable battery is based upon lithium/manganesedioxide, and which further includes a sterile package containing thedisposable battery.
 14. A surgical instrument for removing live humanbone or hard tissue, comprising: a handpiece including: a first endsupporting a rotary driven tool configured to remove live human bone orhard tissue by rotation of a cutting member in response to rotary drivemeans within the handpiece; and a second end having: an alignment postextending therefrom and defining a handpiece longitudinal axis; and aplurality of handpiece electrical contacts arranged concentric to thehandpiece longitudinal axis; and a sterile, disposable battery packincluding: lithium/manganese dioxide batteries; and an attachment endconfigured to be secured to the handpiece second end by means of arotating movement of the disposable battery pack relative to thehandpiece, the attachment end having: an opening therein defining abattery pack longitudinal axis; and a plurality of battery packelectrical contacts arranged concentric to the battery pack longitudinalaxis; wherein the attachment end opening is configured to receive thehandpiece alignment post so as to establish a mutual alignment axisbetween the handpiece longitudinal axis and the battery packlongitudinal axis; and the pluralities of the handpiece and battery packcontacts are mating pluralities of contacts configured to be lockinglyand conductively interengaged in response to the rotating movement. 15.The surgical instrument of claim 14 wherein the handpiece and thedisposable battery pack each have a substantially non-circular externalcross-sectional configuration and provide a substantially continuousexternal surface when the pluralities of handpiece and battery packcontacts are lockingly and conductively interengaged.
 16. The surgicalinstrument of claim 14 wherein the handpiece second end includes firstflat end surfaces and the disposable battery pack includes second flatend surfaces configured for abutting engagement with the first flat endsurfaces while allowing rotation of the battery pack relative to thehandpiece.